Complementary metal-oxide-semiconductor (CMOS) is a technology for constructing digital integrated circuits (IC) such as microprocessors, microcontrollers, and others, or analog circuits such as image sensors, data converters, and transceivers for many types of communication. An IC may comprise digital logic parts such as transistors, plus other components such as resistors and capacitors, connected together by metal layers.
Many kinds of capacitors such as metal-oxide-semiconductor (MOS) capacitors, PN junction capacitors, polysilicon-insulator-polysilicon (PIP) capacitors, and metal-insulator-metal (MIM) capacitors are used in semiconductor devices. In particular, the MIM capacitor offers reduced electrode resistance with wide ranges of applications.
An IC may comprise a plurality of contacts interconnected by multiple metal layers, which are separated by dielectric layers made of insulating materials forming inter-metal dielectric (IMD) layers. Interconnections between different metal layers are made by vias, which go through insulating dielectric layers. Vias allow for communications between devices such as capacitors formed at metal layers to communicate with other devices in the metal layers or directly with the semiconductor devices in the substrate.
Leakage current due to MIM capacitor defects can cause problems for the systems containing the MIM capacitors. To ensure a high product yield, it is desirable for an MIM capacitor to be able to self repair in the event of current leakage. There is a continuing need in the semiconductor device processing art for improved MIM capacitor structures and manufacturing processes to improve the yield in the event of current leakage.
Corresponding numerals and symbols in the different figures generally refer to corresponding parts unless otherwise indicated. The figures are drawn to clearly illustrate the relevant aspects of the preferred embodiments and are not necessarily drawn to scale.